It is known to form equipment towers by stacking precast concrete tower segments to a desired height. The segments may be identical, or they may have reduced diameters over the height of the tower. U.S. Pat. No. 9,175,670 B2 issued on Nov. 3, 2015, to Lockwood, et al. describes a post-tensioned concrete tower formed by stacking precast concrete annular segments on a foundation, wherein the diameter of the respective segments varies in stages over the height of the tower, with a group of segments having one diameter being separated from a group of segments having a different diameter by a transition segment. This tower geometry simplifies the formwork used to precast the segments when compared to tower designs wherein each segment is different as the tower varies gradually in diameter over the height of the tower.
It is also known to provide a ladder in the interior of an equipment tower to facilitate access from ground level to equipment mounted at the top of the tower, for example a wind turbine installed on a nacelle of the tower. Such ladders are typically installed in the tower after the tower has been erected, or they may be installed in stages as the tower is erected.
U.S. Pat. No. 6,782,667 B2 issued on Aug. 31, 2004 to Henderson describes a tower design utilizing telescoping tower sections that are nested within each other while in a horizontal position and which are then extended to a full height after being rotated to a vertical orientation. Henderson also describes a nested telescoping ladder design which has sections corresponding to the nested tower sections which are extended to a full length as the tower sections are extended. The ladder is uniquely designed for use with the telescoping tower sections, and a complicated arrangement of pivot members, slotted and solid brackets, folding brackets, removable plates and stop blocks are required to accomplish its extension and support functions.
Accordingly, further improvements in equipment tower ladder design and installation are desired.